Microstructure and oxidation resistance of porous NbAl3 intermetallic prepared by thermal explosion reaction

Porous Nb-Al intermetallic was prepared by thermal explosion (TE) of combustion synthesis (CS). The temperature profile, phase composition, open porosity and oxidation resistance of Nb-Al compact were investigated. The results showed that the significant exothermic reaction occurred, which means that an obvious TE appeared during heating. The volume expansion of 190% was observed, and the prepared sample exhibited interconnected pores with an open porosity of 65.7%. The porous NbAl 3 intermetallic showed 'pest' oxidation in the temperature range of 500-600°C, and followed the parabolic oxidation law at 400°C. Moreover, due to the highly porous structure, this material had great potential for application to separation and heat insulation at a temperature range of room temperature to 400°C.